empiricist approaches to knowledge acquisition. I say " appears" because so often the debaters seem to be talking past each other, arguing about different things or misunderstanding each other in such basic ways that the debates can seem to an observer as incoherent. For these reasons there has been a powerful need for a systematic treatment of the different senses of nativism and empiricism that considers both their historical contexts and their current manifestations. Cowie's book offers such a treatment, one that goes far beyond prior attempts. It is a remarkably clear and insightful exposition and critique of nativist views from earliest writings to the most current debates. It helps all of us understand better what others are talking about when they don't subscribe to our brand of nativism or empiricism. It also reveals just how much theoretical and empirical work needs to be done before we can get a clear handle what is really the truth about the innateness of language, mathematics, folks psychology, and many other potential domains. Yet, despite these powerful virtues, the book also falls short on some key issues that seem necessary to laying an agenda for future empirical or theoretical work on nativism. I will tend to focus in this essay on those missing links, while also repeatedly stating that this book represents a major leap forward in making sense of what it means to say that some aspect of the mind is innate. Mystery and Modularity.